Importance of screening for macroprolactin in all hyperprolactinaemic sera
- Author:
Farhi Ain Jamaluddin
;
Pavai Sthaneshwar
;
Zanariah Hussein
;
Nor’ashikin Othman
;
Chan Siew Peng
- Publication Type:Journal Article
- Keywords:
Macroprolactin;
hyperprolactinaemia;
PEG precipitation;
Gel fi ltration chromatography
- From:The Malaysian Journal of Pathology
2013;35(1):59-63
- CountryMalaysia
- Language:English
-
Abstract:
Introduction: Prolactin (PRL) exists in different forms in human serum. The predominant form
is monomeric PRL (molecular mass 23 kDa) with smaller amounts of big PRL (molecular mass
50–60 kDa) and at times macroprolactin (molecular mass 150–170 kDa). Macroprolactin, generally
considered to be biologically inactive, accounts for the major part of prolactin in some patients.
Different immunoassays for prolactin differ in reactivity with this macromolecular complex. Aim:
The present study was undertaken to assess the incidence of macroprolactinaemia in our cohort
of hyperprolactinemic patients. Method: 204 samples with hyperprolactinemia were evaluated for
macroprolactinemia by polyethylene glycol (PEG) precipitation and gel fi ltration chromatography
(GFC). Recoveries <60% after PEG precipitation were considered to have macroprolactinaemia.
Results: A total of 43 (21%) of these patients had less than 60% recovery after PEG precipitation.
GFC confi rmed that in seven of these patients macroprolactin was the major part of the prolactin.
Recoveries were < 40% PEG precipitation in these samples. Combined macro and hyperprolactinemia
was observed in two samples and the recovery after PEG precipitation was >40% but 50%. The
incidence of macroprolactinemia in our cohort of hyperprolactinaemic patients was noted to be 4.4%.
Conclusion: Macroprolactin is a signifi cant cause of misdiagnosis, unnecessary investigation, and
inappropriate treatment and hence it is useful to screen all patients with high PRL levels with PEG
precipitation and to apply GFC to samples with recoveries <50%.
- Full text:P020150925355916380595.pdf
